This invention relates generally to mobile rocking wheelchairs and more particularly, relates to a wheelchair of the character described which has releasable means for selectively locking the chair seat against rocking motion in a substantially non-inclined position which enables the occupant to move or be moved out of the chair more easily and readily. The wheelchair embodying the invention is further characterized by a construction which is economical and sturdy so as to be attractive for use by occupants in hospitals, nrusing homes and/or by disabled persons.
It is known that rocking and/or bouncing motion can render therapeutic and/or relaxing benefits for handicapped persons, such as those having muscle, spinal, and/or other disorders. Persons having such disorders commonly are confined to a wheelchair for their transportation because they are not ambulatory. When it is desired to provide such persons with the benefits of rocking and/or bounding motion, it has been necessary to physically move such persons from conventional wheelchairs to other seating devices which enable the handicapped person to rock and/or bounce in the seating device, as desired.
Stationary chairs with rockable or tiltable seats are well known, such as representated by U.S. Pat. Nos. 4,167,288 or 3,637,255 for instance. Rocker-type wheelchairs are known generally, such as represented by U.S. Pat. Nos. 4,118,046, 3,455,600, 3,712,671, 3,415,531.
U.S. Pat. Nos. 4,544,200 and 3,917,312 disclose wheelchairs with spring assemblies for desired movement by the user. U.S. Pat. No. 4,477,118 discloses an office-type chair providing a controlled tilt rocker on a mobile pedestal.
U.S. Pat. No. 3,379,473 discloses a stationary chair which has locking means for locking the chair against rocking movement when it is moved into its reclining position. U.S. Pat. No. 4,383,714 shows a rockable chair on a wheeled pedestal and which has a locking feature to lock the backrest in various inclined positions, but the locking feature is not concerned with rocking movement of the chair.
U.S. Pat. No. 3,848,924 discloses a mobile, reclining platform rocking chair which includes means for preventing movement of the chair when the leg rest is partially or fully retracted.
The wheelchair embodying the invention utilizes a simple and economical parallel four bar linkage assembly for achieving controlled rocking movement of the chair seat. The parallel linkage assembly is operationally mounted to a horizontal cross-strut or member supported on the vertical standard of a mobile pedestal. A chair seat support frame is operationally connected to said assembly with a chair seat and backrest mounted on said support frame. A releasable locking mechanism is provided for locking the chair seat against rocking movement in a substantially nonreclining or inclined position so as to permit a user easily and readily to lift his body off of the seat by arm movement pressing downwardly on adjacent armrests of the chair for egress from the chair. The locking mechanism is located within convenient reach of the occupant of the chair.
Further, the wheelchair embodying the invention has removable and laterally adjustable armrest members mounted on the support frame for lateral egress from the chair or for accommodating patients of larger girth. The wheels of the mobile pedestal have conventional locking members for restraining movement of the chair when a patient wishes to leave the chair or a patient enters the chair.
All of these advantages are achieved while still providing a wheelchair characterized further by its sturdy and reliable appearance.